Problems / number-theory
number-theory / Diophantine approximation; irrationality of L-values
Irrationality of Catalan's constant
Theorem 1.1: G is irrational. Under the hypothesis G∈Q the paper builds mixed determinants ΔN of size 48N from moments of two kernels, whose ζ(2) terms cancel by Taylor contact of Chebyshev rows, so all ΔN are rational; a finite certificate gives Δp=0 for large primes p, prime-by-prime denominator bounds give liminfLp>−2.29084, and a real-place integral estimate gives limsupLN<−2.2909, a contradiction. Corollaries: 4G, the minimal volume of a two-cusped orientable hyperbolic 3-manifold, and every arithmetic hyperbolic 3-orbifold volume over Q(i) are irrational. Not shown: an irrationality measure, transcendence, or anything about β(4),β(6),…. An earlier preprint by Zhi-Wei Sun (arXiv:2609.04176, 3 September 2026) also claims irrationality; the manuscript says it uses nothing from it, so the first claimed proof may not be this one.